JP2007056746A - Vacuum generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum generator capable of realizing quick rise and decay of vacuum and excellent high speed response characteristic. <P>SOLUTION: This vacuum generator provided with a supply port 10 for generating vacuum, a vacuum port 50, a supply port 14 for vacuum break for supplying destroying air into the vacuum port, and an exhaust port 40 is provided with a diffuser spool 30 and a nozzle 32 for jetting compressed air supplied from the supply port 10 for generating vacuum toward the diffuser spool 30 as an ejector mechanism. The diffuser spool 30 and the nozzle 32 are formed as shutoff valves for controlling communication between the vacuum port 50 and the supply port 14 for vacuum break by moving to a closing position for shutting off communication between the supply port 14 for vacuum break and the vacuum port 50 when compressed air is fed into the supply port 10 for generating vacuum and moving to an opening position for communicating the supply port 14 for vacuum break and the vacuum port 50 when feeding of compressed air into the supply port 10 for generating vacuum is stopped. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vacuum generator that is used in a transport device that transports workpieces such as parts by vacuum suction.

  2. Description of the Related Art A vacuum generator that generates a vacuum using compressed air as an air source is widely used in a transport apparatus that transports workpieces such as parts by vacuum suction. The simplest vacuum generator has a nozzle and diffuser in the main body, and is configured to send compressed air from the supply port into the main body and generate negative pressure in the vacuum port by the ejector action. Is. However, in the vacuum generator having such a configuration, the workpiece adsorbed to the vacuum port is detached by stopping the supply of compressed air to the supply port and communicating the atmosphere from the exhaust port to the vacuum port side. Therefore, there is a problem that the responsiveness when the workpiece is detached is low.

As a method for improving the responsiveness when the workpiece is detached from the vacuum port, there is a method of forcibly sending breakage air into the vacuum port when the vacuum port is broken. As a vacuum generator according to this method, there is an apparatus configured to use a pilot valve to switch an air flow path at the time of vacuum generation and vacuum break so that compressed air is supplied to the vacuum port side at the time of vacuum break (patent) References 1 and 2).
JP 2002-224984 A JP 2003-42134 A

  However, the vacuum generator configured to switch the air flow path using the pilot valve and supply the rupture air to the vacuum port side at the time of the vacuum break has a problem that the configuration of the apparatus becomes complicated and the flow path is switched. Because of the configuration, the flow path through which the break air flows from the supply port to the vacuum port is lengthened, and the responsiveness at the time of vacuum break is reduced, and the communication flow path is lengthened even when a vacuum is generated There is a problem that responsiveness decreases.

  As a vacuum generator for solving such a problem, there is a vacuum generator provided with a shuttle valve 5 and a tank 6 as shown in FIG. In this vacuum generator, when compressed air is supplied to the compressed air supply port P, the compressed air is supplied to the tank 6 via the shuttle valve 5, and at the same time, the compressed air is supplied to the ejector 7 so that the vacuum port (V) is supplied. Becomes a negative pressure and the supply of compressed air to the supply port (P) is stopped, the shuttle valve 5 moves to a position where the tank 6 and the vacuum port (V) communicate with each other, and the vacuum port (V The air is supplied to the vacuum port (V) and the vacuum air is supplied to the vacuum port (V).

  Thus, in the case of this vacuum generator, the break air is supplied from the tank 6 to the vacuum port (V), so that the high-speed response at the time of vacuum break is better than that of a simple type vacuum generator. Become. However, in this vacuum generator, since the shuttle valve 5 and the tank 6 are provided in addition to the ejector 7, formation of the apparatus in a compact manner is hindered, and between the shuttle valve 5 and the vacuum port (V). If the flow path cannot be shortened, there is a problem that the response at the time of vacuum breakage becomes insufficient.

  Therefore, the present invention has been made to solve these problems, and it is possible to simplify the configuration of the vacuum generating device and to form the device compactly, and to have high-speed response at the time of vacuum generation and vacuum break. An object of the present invention is to provide a vacuum generator.

The present invention has the following configuration in order to achieve the above object.
That is, a vacuum generation supply port to which compressed air is supplied, a vacuum port in which a vacuum pressure is generated by an ejector mechanism built in the main body, a vacuum break supply port for supplying break air to the vacuum port, and an exhaust port The ejector mechanism includes a diffuser spool and a nozzle that injects compressed air supplied from the vacuum generation supply port toward the diffuser spool, and the diffuser spool and the nozzle are configured as described above. When compressed air is fed into the vacuum generation supply port, the vacuum break supply port and the vacuum port are moved to a closed position where the communication between the vacuum break supply port and the vacuum port is cut off. When the feeding is stopped, the vacuum break supply port and the vacuum port are moved to an open position for communication. Ri, characterized in that it is formed as a shut-off valve for controlling communication between the vacuum port and said vacuum break for supply port.

The diffuser spool and the nozzle are mounted in a mounting hole that communicates the vacuum generation supply port and the exhaust port so as to be movable back and forth in the axial direction, and the outer surface of the diffuser spool and the inner surface of the mounting hole A communication channel is provided between the peripheral surface and the first flow channel communicating with the vacuum break supply port and the second flow channel communicating with the vacuum port, and the outer periphery of the diffuser spool is provided. A valve portion that opens and closes the communication flow path as the diffuser spool moves forward and backward is provided on the surface and the inner peripheral surface of the mounting hole.
The diffuser spool and the nozzle are inserted into a sleeve fitted into the mounting hole, and the valve portion is provided between the outer peripheral surface of the diffuser spool and the inner peripheral surface of the sleeve. It is characterized by that.
The sleeve is provided with an opening that communicates with an inlet provided in the diffuser spool, the valve portion is provided in front of the opening, and the diffuser spool moves to the forward position when the diffuser spool moves to the forward position. The communication channel is closed, and the communication channel is opened when the diffuser spool moves to the retracted position.

The diffuser spool is equipped with a biasing means that always moves the diffuser spool to the closed position, so that the diffuser spool and the nozzle return to the original position and act as a required shut-off valve. .
In addition, since the flow restrictor is provided in communication with the second flow path that communicates with the vacuum break supply port, it is possible to accurately break the vacuum by adjusting the flow rate of the break air during the vacuum break. it can.

  Also, a supply pipe connected to the compressed air supply source side is connected to the supply port for vacuum generation, and only air flows in one direction from the supply pipe to the vacuum generator main body. Since the branch pipe is connected via a check valve that allows the residual pressure, the residual pressure due to the compressed air supplied to the branch pipe can be used as the breaking air at the time of vacuum break, and the length of the branch pipe is adjusted appropriately By doing so, it is possible to easily adjust the discharge time of the break air without changing the flow rate of the break air.

  According to the vacuum generator of the present invention, the diffuser spool and the nozzle constituting the ejector mechanism are provided so as to act as a shut-off valve for controlling communication between the vacuum break supply port and the vacuum port. It is possible to simplify the configuration of the device and make the device compact, shorten the flow path length in the main body of the vacuum generator, fast rise and fall of the vacuum generator, fast response It can be provided as a vacuum generator with excellent characteristics.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a vacuum generator according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows the overall configuration of an embodiment of a vacuum generator according to the present invention. The vacuum generator of the present embodiment is connected to a vacuum generator main body 60, a vacuum generation supply port 10 provided in the main body 60, and a supply pipe 12 for supplying compressed air to the vacuum generation supply port 10. The vacuum break supply port 14 provided in the main body 60 is connected to the vacuum break supply port 14 and has branch pipes 16a and 16b for supplying vacuum break air.

One end of the supply pipe 12 is connected to the vacuum generation supply port 10, and the other end is connected to one branch portion 22 a of the branch pipe joint 22.
The branch pipes 16a and 16b are formed in a single tube shape via a check valve 18 that allows only air flow in one direction toward the main body 60, and one end of the branch pipe 16a is connected to the vacuum break supply port 14. The other end of the branch pipe 16 b is connected to the other branch portion 22 b of the branch pipe joint 22. The check valve 18 is formed in a joint structure including a locking claw and an opening ring.
A tubular body 20 connected to the compressed air supply source side is connected to the proximal end portion 22 c of the branch pipe joint 22. A valve (not shown) for controlling the supply timing of the compressed air to the pipe body 20 is provided on the compressed air supply source side, and the supply pipe 12 and the branch pipes 16b and 16a are connected via the branch pipe joint 22. The supply of compressed air is controlled. In FIG. 1, the lower half of the center line shows a state where compressed air is supplied from the tube body 20, and the upper half shows a state where supply of compressed air from the tube body 20 is stopped.

FIG. 2 shows the configuration of the main body 60 of the vacuum generator.
The vacuum generation supply port 10 and the vacuum break supply port 14 are arranged in parallel on one end side of the main body 60, and the exhaust port 40 and vacuum port 50 are arranged in parallel on the other end side of the main body 60. Is done.
The main body 60 is provided with a mounting hole 60a through which the ejector mechanism is incorporated, the vacuum generation supply port 10 is provided at one end of the mounting hole 60a, and the exhaust port 40 is provided with the mounting hole 60a. Is provided on the other end side.
The vacuum generation supply port 10 is formed in a joint structure including a locking claw 10a and an opening ring 10b.
The exhaust port 40 is airtightly closed by a lid 42 at the end of a cylindrical portion 60b formed to extend from the main body 60 in a cylindrical shape, and an exhaust hole 44 is provided in a slit shape on the side surface of the cylindrical portion 60b. The silencer element 46 is attached to the inner surface of the cylindrical portion 60b so as to close the exhaust hole 44.

Similarly to the vacuum generation supply port 10, the vacuum break supply port 14 is formed in a joint structure including a locking claw 14a and an open ring 14b.
Moreover, the vacuum port 50 is formed in the joint structure provided with the latching claw 50a and the release ring 50b at the end of the connection pipe 51a connected to the attach port 51 formed in the same joint structure. Inside the vacuum port 50, a filter 51b that protects dust from entering the main body 60 together with air when air is sucked from the vacuum port 50 is mounted.

In the ejector mechanism attached to the mounting hole 60a, the diffuser spool 30 and the nozzle 32 are arranged movably in the axial direction of the mounting hole 60a, and the through hole 30a and the vacuum port 50 provided in the diffuser spool 30 are connected to the first flow path. It is configured by communicating via a path 52.
In the present embodiment, the first sleeve 34 is fitted into the mounting hole 60a, and the diffuser spool 30 and the nozzle 32 are mounted on the first sleeve 34 so as to be movable in the axial direction. The diffuser spool 30 is movably provided in the axial direction while being air-sealed with the inner peripheral surface of the first sleeve 34 by a packing 30b mounted on the outer peripheral surface, and the nozzle 32 is a seal member 32a mounted on the outer peripheral surface on the base end side. Thus, the first sleeve 34 is movably provided in the axial direction while being air-sealed with the inner peripheral surface of the first sleeve 34.

  The front end portion of the diffuser spool 30 is formed with a slightly reduced diameter, and a spring 31 as an urging means is extrapolated to the reduced diameter portion. The spring 31 is mounted so as to spring between the locking step formed at the proximal end of the reduced diameter portion and the lid 42 attached to the cylindrical portion 60b. As a result, the diffuser spool 30 and the nozzle 32 disposed in contact with the rear end surface of the diffuser spool 30 are always urged rearward (vacuum generation supply port 10 side). The rearward movement position (retreat position) of the diffuser spool 30 and the nozzle 32 is regulated by the rear end surface of the nozzle 32 coming into contact with the front end surface of the second sleeve 35 that is fitted into the first sleeve 34 and attached. Is done.

FIG. 3 shows an enlarged structure in the vicinity of a portion where the diffuser spool 30 and the nozzle 32 are combined.
The first flow path 52 that communicates with the vacuum port 50 and is provided in the main body 60 is bent from the vacuum port 50 toward the first sleeve 34, and is in an opening 34 a provided in the first sleeve 34. The end opens. The diffuser spool 30 is provided with an introduction port 30c that opens on the side of the ejection end of the nozzle 32, and the opening 34a and the introduction port 30c are arranged close to each other.

A step protrusion 30d is provided on the front side of the introduction port 30c of the diffuser spool 30, and a seal member 36 such as an O-ring is fitted around the outer surface of the diffuser spool 30 at a portion where the step protrusion 30d is provided. The The first sleeve 34 is provided with a valve seat 34b that contacts the seal member 36 that is fitted to the step protrusion 30d so that the seal member 36 abuts to open and close the air flow path.
The part of the diffuser spool 30 where the step protrusion 30d is formed and the part sandwiched between the packing 30b and the outer peripheral surface are slightly reduced in diameter so that a communication channel is formed between the inner peripheral surface of the first sleeve 34. It is formed in the reduced diameter portion 30e. The first sleeve 34 is formed with a communication hole 34c that communicates with a portion where the reduced diameter portion 30e is formed.

  The communication hole 34 c communicates with the vacuum break supply port 14 via a second flow path 54 formed in the main body 60. The second flow path 54 is provided so as not to intersect the first flow path 52 in the main body 60 and communicates with the vacuum break supply port 14 via the needle valve 56 as shown in FIG. The needle valve 56 is provided for adjusting the flow rate of the vacuum breaking air, and is provided so as to be able to adjust the flow rate of the vacuum breaking air by moving back and forth in the axial direction.

Then, the effect | action of the vacuum generator mentioned above is demonstrated.
FIG. 1 shows a state in which the supply pipe 12 and the branch pipes 16 a and 16 b are mounted on the main body 60. The supply pipe 12 and the branch pipes 16a and 16b can be easily mounted by simply inserting a pipe body into the port due to the joint structure of the vacuum generation supply port 10 and the vacuum break supply port 14. When the tubular body is removed from the port, the release rings 10b and 14b may be pushed inward to release the lock by the locking claws 10a and 14a, and the tubular body may be pulled out.
By connecting a supply source of compressed air to the branch pipe joint 22, the vacuum generator is used.

First, when compressed air is supplied from the compressed air supply source via the pipe body 20, the compressed air is branched by the branch pipe joint 22 and supplied to the supply pipe 12 and the branch pipes 16b and 16a.
As shown in FIG. 2, the compressed air supplied to the supply pipe 12 is sent to the vacuum generation supply port 10 to generate a vacuum pressure at the vacuum port 50.
That is, the nozzle 32 moves forward by the pressure of the compressed air sent to the vacuum generation supply port 10, and the valve member 34 b provided on the first sleeve 34 is provided with the seal member 36 fitted to the step protrusion 30 d of the diffuser spool 30. Abut. As a result, as shown in FIG. 3, the communication flow path 53 formed between the communication hole 34c and the opening 34a is closed, and the communication between the second flow path 54 and the first flow path 52 is prevented. The first flow path 52 communicates with the diffuser spool 30 through the opening 34a and the introduction port 30c. That is, the vacuum port 50 communicates with the ejector mechanism, and the vacuum break supply port 14 and the vacuum port 50 are shut off.

  The position where the diffuser spool 30 and the nozzle 32 advance and the seal member 36 fitted to the step protrusion 30d of the diffuser spool 30 contacts the valve seat 34b provided on the first sleeve 34 is located at the position where the diffuser spool 30 and the nozzle 32 are in contact. Is moved to the forward position (closed position). The seal member 36 and the valve seat 34b serve to open and close the communication channel 53 that connects the first channel 52 and the second channel 54, and are provided as a valve unit that opens and closes the communication channel 53. It has been. The function of the valve portion can also be achieved by providing a valve seat on the diffuser spool 30 and providing a seal portion such as an O-ring on the first sleeve 34.

The compressed air that is injected from the nozzle 32 to the diffuser spool 30 is discharged to the outside from the exhaust port 40 through the silencer element 46 by setting the vacuum port 50 to a vacuum pressure by an ejector action (vacuum generation operation). The arrows in FIGS. 2 and 3 indicate the ejector action by the compressed air.
This ejector action is performed by sending compressed air into the vacuum generating supply port 10, and the diffuser spool 30 and the nozzle 32 are resisted by the spring 31 by the compressed air feeding pressure. Advances, shuts off the vacuum break supply port 14 and the vacuum port 50, and supplies compressed air only from the vacuum generation supply port 10 into the main body 60 to generate a vacuum.

The vacuum generation state is released by stopping the supply of compressed air from the compressed air supply source. FIG. 4 shows a state immediately after the supply of compressed air is stopped.
When the supply of compressed air is stopped, the diffuser spool 30 and the nozzle 32 move to the retracted position (open position) where the rear end surface of the nozzle 32 abuts on the end surface of the second sleeve 35 by the elastic action of the spring 31.
When the diffuser spool 30 moves to the retracted position, the valve seat 34b and the seal member 36 are separated from each other, and the second flow path 54 communicates with the first flow path 52 through the communication hole 34c and the opening 34a. That is, the vacuum break supply port 14 and the vacuum port 50 communicate with each other.

When the vacuum break supply port 14 and the vacuum port 50 communicate with each other, the compressed air remaining in the branch pipe 16 a shown in FIG. 1 passes through the second flow path 54 and the first flow path 52 to the vacuum port 50. Supplied. The action of the compressed air remaining in the branch pipe 16a being supplied to the vacuum port 50 is that the check valve 18 prevents the compressed air remaining in the branch pipe 16a from flowing back to the branch pipe 16b, and the residual pressure in the branch pipe 16a Is supplied.
That is, when the supply of compressed air to the vacuum generation supply port 10 is stopped, the diffuser spool 30 and the nozzle 32 communicate with the vacuum port 50 and the vacuum break supply port 14 (positions for opening the vacuum break circuit). ) And the compressed air remaining in the branch pipe 16a is supplied as the breaking air from the vacuum breaking supply port 14 to the vacuum port 50, and is vacuum broken. FIG. 4 shows the flow of breaking air by broken lines.

FIG. 5 shows a circuit diagram of the vacuum generator of this embodiment. The vacuum generation valve 8 is provided on the compressed air supply source side, and the vacuum break supply port 14 is connected to the compressed air supply source side via the check valve 18.
A characteristic configuration of the vacuum generator according to the present embodiment is that the diffuser spool 30 and the nozzle 32 constituting the ejector mechanism serve as a shut-off valve 300 that controls communication between the vacuum port 50 and the vacuum break supply port 14. It also has a function that works.

  The figure shows a state in which the vacuum break supply port 14 and the vacuum port 50 communicate with each other through the shutoff valve 300 in a state where compressed air is not supplied to the vacuum generation supply port 10 (at the time of vacuum break). . When compressed air is supplied, the shut-off valve 300 shuts off between the vacuum break supply port 14 and the vacuum port 50, and the compressed air passes through the ejectors 30 and 32 and is discharged from the exhaust port 40. A vacuum pressure is generated at the port 50.

  According to the vacuum generator of this embodiment, the diffuser spool 30 and the nozzle 32 constituting the ejector mechanism are provided with the function as the shutoff valve 300, so that the vacuum generator is compared with the case where the shutoff valve is provided separately. The configuration can be simplified and the apparatus can be made compact. This makes it possible to minimize the volume of the vacuum breaking circuit from the shut-off valve 300 to the vacuum port 50, which has the greatest influence on the response characteristics (rising and falling) of the vacuum generation operation and the vacuum breaking operation. It is possible to rise and fall at high speed.

Further, in the vacuum generator of the present embodiment, the compressed air remaining in the branch pipe 16a connecting the check valve 18 and the vacuum break supply port 14 is used as the breaking air. Therefore, the length and diameter of the branch pipe 16a are used. By adjusting, the amount of breaking air supplied for vacuum breaking can be adjusted. That is, the amount of air supplied as breaking air from the branch pipe 16a increases as the internal volume of the branch pipe 16a increases, and decreases as the internal volume of the branch pipe 16a decreases. For example, by increasing the length of the branch pipe 16a, The amount of the breaking air can be increased, and the discharge time of the breaking air can be extended.
Therefore, according to the vacuum generator of the present embodiment, the amount of air for destruction is adjusted by changing the length and diameter of the branch pipe 16a according to the work contents in the transfer device using the vacuum generator. Therefore, it is possible to adjust the amount of air to be broken and perform an accurate work. The work of exchanging the branch pipes 16a and 16b is extremely easy.

  The supply amount of breaking air to the vacuum port 50 can also be adjusted using a flow rate throttle valve (needle valve 56). By restricting the flow restrictor, the amount of air flowing into the vacuum circuit is reduced, and the discharge time of the breaking air is increased. In this way, by adjusting the flow restrictor, the amount of breaking air supplied to the vacuum port 50 at the time of vacuum break can be adjusted, and appropriate vacuum break can be performed.

FIG. 6 is a circuit diagram showing another configuration example of the vacuum generator using the main body 60 of the vacuum generator described in the above embodiment.
In the embodiment described above, the check valve 18 is used to supply the compressed air in a branched manner from the compressed air supply source to the vacuum generation supply port 10 and the vacuum break supply port 14. In FIG. 6, the vacuum generating valve 8 and the vacuum breaking valve 9 are connected to a compressed air supply source, the compressed air is supplied to the vacuum generating supply port 10 and the compressed air is supplied to the vacuum breaking supply port 14. In this example, the supply is controlled by alternately switching on and off the vacuum generating valve 8 and the vacuum breaking valve 9.

Also in this embodiment, when the diffuser spool 30 and the nozzle 32 constituting the ejector mechanism function as the shutoff valve 300, and compressed air is fed into the vacuum generation supply port 10, the vacuum break supply port When the supply of compressed air to the vacuum generation supply port 10 is stopped, the vacuum break supply port 14 and the vacuum port 50 communicate with each other and the break air is supplied to the vacuum port 50. Supplied.
Since the breaking air is supplied from a compressed air supply source, the flow rate is adjusted by adjusting the opening / closing timing of the vacuum breaking valve 9 and the flow restrictor.

The vacuum generator of the present embodiment is also formed in a very compact manner, and is provided as a vacuum generator with excellent high-speed response for rising and falling of the vacuum.
Moreover, since the vacuum generator according to the present invention is provided as a small vacuum generator incorporating a vacuum generating mechanism and a vacuum breaking mechanism, it can be suitably used as a vacuum generator used at the end of a vacuum pipe. By using it at the end of the vacuum pipe, the volume from the vacuum port to the work can be minimized, and this can also accelerate the rise and fall of the vacuum.

It is explanatory drawing which shows the state which connected the supply pipe and the branch pipe to the main body of the vacuum generator. It is sectional drawing which shows the structure (at the time of vacuum operation | movement) of the main body of a vacuum generator. It is sectional drawing which expands and shows the structure of the main body of a vacuum generator. It is sectional drawing which shows the structure (at the time of a vacuum break) of the main body of a vacuum generator. It is a circuit diagram of a vacuum generator. It is a circuit diagram which shows the structure of other embodiment of a vacuum generator. It is a circuit diagram which shows the structure of the conventional vacuum generator.

Explanation of symbols

10 Vacuum generation supply port 12 Supply pipe 14 Vacuum break supply port 16a, 16b Branch pipe 18 Check valve 22 Branch fitting 30 Diffuser spool 30c Inlet 30d Step projection 31 Spring 32 Nozzle 34 First sleeve 34a Open 34b Valve seat 34c Communication hole 36 Seal member 40 Exhaust port 44 Exhaust hole 46 Silencer element 50 Vacuum port 51 Attached port 51b Filter 52 First channel 54 Second channel 56 Needle valve 60 Main body 60a Mounting hole 60b Cylindrical portion 300 Shut-off valve

Claims (7)

A vacuum generating supply port to which compressed air is supplied, a vacuum port in which a vacuum pressure is generated by an ejector mechanism built in the main body, a vacuum breaking supply port for supplying breaking air to the vacuum port, and an exhaust port In the vacuum generator provided,
The ejector mechanism includes a diffuser spool and a nozzle that injects compressed air supplied from the vacuum generation supply port toward the diffuser spool,
The diffuser spool and nozzle are
When compressed air is sent to the vacuum generation supply port, the vacuum break supply port and the vacuum port are moved to a closed position where communication is interrupted,
When the supply of compressed air to the vacuum generating supply port is stopped, by moving to an open position where the vacuum breaking supply port and the vacuum port communicate with each other,
A vacuum generator characterized by being formed as a shut-off valve for controlling communication between the vacuum port and the vacuum break supply port. The diffuser spool and the nozzle are mounted so as to be movable back and forth in the axial direction in a mounting hole that communicates the vacuum generation supply port and the exhaust port.
A first flow path communicating with the vacuum breaking supply port and a second flow path communicating with the vacuum port are communicated between the outer peripheral surface of the diffuser spool and the inner peripheral surface of the mounting hole. A communication channel is provided,
The valve part which opens and closes the said communication flow path is provided in the outer peripheral surface of the said diffuser spool, and the inner peripheral surface of the said mounting hole with the advance / retreat of the said diffuser spool. Vacuum generator.   The diffuser spool and the nozzle are inserted into a sleeve fitted in the mounting hole, and the valve portion is provided between the outer peripheral surface of the diffuser spool and the inner peripheral surface of the sleeve. The vacuum generator according to claim 2, wherein The sleeve is provided with an opening communicating with the introduction port provided in the diffuser spool,
The valve portion is provided in front of the opening, and the communication flow path is closed when the diffuser spool moves to the forward position, and the communication flow path is opened when the diffuser spool moves to the retracted position. 4. The vacuum generator according to claim 3, wherein:   The vacuum generator according to any one of claims 1 to 4, wherein the diffuser spool is mounted with a biasing means for moving the diffuser spool to a closed position at all times.   2. The vacuum generator according to claim 1, wherein a flow restrictor is provided in communication with the second flow path that communicates with the vacuum break supply port. A supply pipe connected to a supply source side of compressed air is connected to the supply port for vacuum generation,
2. The vacuum according to claim 1, wherein a branch pipe is connected via a check valve which branches from the supply pipe and allows only air flow in one direction toward the main body of the vacuum generator. Generator.

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